JP4333199B2 - Foreign object detection jig, camera body and foreign object detection system for interchangeable lens digital camera - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to detection of foreign matter existing on an imaging optical path and image defect correction in an interchangeable lens digital camera.
[0002]
[Prior art]
In an electronic camera such as a digital camera, if a foreign object adheres to a filter or the like that is on the imaging optical path and is disposed in the vicinity of the image sensor, a shadow caused by the foreign object becomes a defect in the captured image. In particular, in an interchangeable lens type electronic camera, it is difficult to avoid dust or dirt that has entered the mirror box during lens replacement. In order to solve such a problem, an electronic camera that detects the position of a foreign object existing on the imaging optical path and corrects a defect in a captured image caused by the foreign object is known. This electronic camera images a shadow of a foreign object using an illumination light source provided in the camera body, and detects the position of the foreign object from the captured image (Patent Document 1).
[0003]
[Patent Document 1]
JP 2002-374445 A
[0004]
[Problems to be solved by the invention]
In the electronic camera described in Patent Document 1, it is necessary to incorporate a dedicated light source in the camera body. Therefore, the present invention cannot be applied to an existing electronic camera that does not incorporate a light source. In addition, since the electronic camera has a built-in light source, the structure of the camera body becomes complicated, leading to an increase in the cost of the camera body.
[0005]
The present invention provides a foreign object detection jig and a camera body capable of detecting a foreign object on an imaging optical path without incorporating a dedicated light source in the camera body in an interchangeable lens digital camera.
[0006]
[Means for Solving the Problems]
  The foreign matter detection jig according to the first aspect of the invention is used for detecting foreign matter existing on the imaging optical path of the interchangeable lens digital camera, and is attached to the lens mount portion of the digital camera, and the lens mount is mounted by the attachment means. A light source located on the optical axis of the imaging optical path when attached to the part;A power supply terminal that supplies power to the light source from the outsideIs provided.
  A foreign matter detection jig according to a second aspect of the present invention is used for detecting foreign matter existing on an imaging optical path of a lens-interchangeable digital camera, and is attached to a lens mount portion of the digital camera. A light source positioned on the optical axis of the imaging optical path when attached to the part, and a pilot lamp that indicates the lighting state of the light source to the outside.
  A foreign matter detection jig according to a third aspect of the invention is used for detecting foreign matter existing on an imaging optical path of a lens-interchangeable digital camera, and is attached to a lens mount portion of the digital camera. A light source positioned on the optical axis of the imaging optical path when attached to a part, a switch for switching on / off of the light source by a user operation, and auto power for turning off the light source after a certain time has elapsed since the light source was turned on Off means.
  According to a fourth aspect of the present invention, there is provided a foreign object detection jig used for detecting a foreign object existing on an imaging optical path of a lens-interchangeable digital camera. A light source positioned on the optical axis of the imaging optical path when attached to the part and a signal input terminal for instructing to turn on / off the light source from the outside are provided.
  Claim 5The invention ofAny one of claims 2-4The foreign matter detection jig further includes power supply means for supplying power to the light source.
  Claim 6The invention ofClaims 1-5In any of the foreign matter detection jigs, the light source is a light source that emits white or green light.
  Claim 7The invention ofClaims 1-6In the interchangeable lens digital camera main body that images a foreign object existing on the imaging optical path using any of the foreign object detection jigs, mode selection means for selecting a foreign object detection mode for imaging a foreign object by a user operation; Mode setting means for setting the mode selected by the mode selection means.
  Claim 8The invention ofClaims 1-6In the interchangeable-lens digital camera body that images a foreign object existing on the imaging optical path using any of the foreign object detection jigs, when a foreign object detection jig is attached, a foreign object detection mode is set for imaging the foreign object. Mode setting means is provided.
  Claim 9The invention ofClaim 7 or 8The camera body further includes an imaging condition setting means for setting an imaging condition for imaging a foreign object when the foreign object detection mode is set.
  Claim 10The invention ofClaim 4The lens-interchangeable digital camera main body that images a foreign object existing on the imaging optical path using the foreign object detection jig includes a lighting control unit that controls lighting of the light source when imaging the foreign object.
  Claim 11The invention ofClaim 10The camera main body further includes mode setting means for setting a foreign object detection mode for imaging a foreign object, and imaging condition setting means for setting an imaging condition for imaging the foreign object when the foreign object detection mode is set. Is.
  Claim 12The invention ofClaim 11In the camera body ofIn advanceWhen the set conditions are met and a foreign object detection jig is attached,Foreign matter detection mode by mode setting meansIn the imaging conditions set by the imaging condition setting meansForeign matter imaging command means for commanding imaging of the foreign matter is further provided.
  Claim 13The invention ofClaims 7-12The camera body further includes recording control means for recording information on the aperture and exit pupil distance at the time of imaging together with the captured image.
  Claim 14The invention ofClaim 13In the camera body, the recording control means records an individual number or individual symbol for identifying the individual camera body together with the captured image.
  Claim 15The foreign object detection system of the interchangeable lens digital camera according to the invention ofClaims 1-6A foreign matter detection jigClaims 7-14The camera main body is provided.
[0007]
DETAILED DESCRIPTION OF THE INVENTION
-First embodiment-
A first embodiment of a foreign object detection system to which the present invention is applied is shown in FIG. In this foreign object detection system, a light source is provided on a body cap attached to a camera body of a digital camera, and an image for detecting a foreign object on an imaging optical path is taken by using the body cap as a jig. Further, a shadow caused by the foreign matter is detected from the captured foreign matter detection image, the position of the foreign matter on the imaging optical path is calculated from the position of the shadow, and the image defect due to the foreign matter in the captured image is corrected. The foreign object detection system in FIG. 1 includes a camera body 1, a body cap 2, a lens 3, a personal computer 4, a monitor 5, and a memory card reader 6. The camera body 1 is a camera body of a commonly used interchangeable lens digital camera, and includes a lens mount unit 11, an imaging unit 12, a memory card 13, an output interface 14, and a control unit 17.
[0008]
The lens mount portion 11 is a portion for attaching the body cap 2 and the lens 3 to the camera body 1. The body cap 2 and the lens 3 are provided with a mechanism for attaching to the lens mount unit 11, and these can be arbitrarily exchanged and attached to the lens mount unit 11. The body cap 2 is a cap for protecting the inside of the camera body 1 when the lens 3 is not attached, and is also used as a jig for capturing a foreign object detection image as will be described later. The lens 3 is an imaging interchangeable lens, and various lenses are used depending on the purpose of imaging.
[0009]
The imaging unit 12 captures an image of a subject input from the outside through the lens 3 attached to the lens mount unit 11, and outputs the captured image data to the memory card 13. The imaging unit 12 includes an imaging element such as a CCD, and an optical member such as an optical filter disposed in front of the imaging element. This optical member is on the imaging optical path, and when the lens 3 is replaced, foreign matter such as dust or dust entering the mirror box (not shown) may adhere. When a shadow due to these foreign matters attached to the optical member is imaged, that portion of the captured image becomes an image defect. In order to solve such problems, the imaging unit 12 uses a body cap 2 as a jig in addition to a normal captured image, and later describes a foreign matter detection image for detecting foreign matter attached to the optical member. The image is taken as described above. The imaging unit 12 is controlled by the control unit 17.
[0010]
The memory card 13 records the foreign object detection image and the captured image data output from the imaging unit. The memory card 13 can be removed from the camera body 1, and the recorded image data can be read into the personal computer 4 by attaching the removed memory card 13 to the memory card reader 6. Further, these image data recorded on the memory card 13 can be directly output to the personal computer 4 via the output interface 14. For the memory card 13, for example, a recording device represented by CompactFlash (registered trademark), SmartMedia (registered trademark), or the like is used.
[0011]
The personal computer 4 reads the foreign object detection image and captured image data recorded on the memory card 13 via the memory card reader 6 or the output interface 14 and executes a foreign object detection program. By executing the foreign object detection program, the personal computer 4 calculates the position of the foreign object on the imaging optical path attached to the optical member using the foreign object detection image, and corrects the image defect of the captured image based on the detection result. . The image data read into the personal computer 4 and the captured image data whose image defects have been corrected by the foreign object detection program are recorded on a recording device such as an internal hard disk and displayed on the monitor 5. The imaging method for the foreign object detection image, the foreign object position calculation method, and the image defect correction method at this time will be described in order below.
[0012]
(1) Taking a foreign object detection image
An example of the body cap 2 used as a jig for capturing a foreign object detection image is shown in FIG. Inside the body cap 2, an LED 21, a pilot lamp 22, a switch 23, a battery 24, and an electric circuit board 25 are provided. The mounting direction when the body cap 2 is mounted on the lens mount portion 11 in FIG. 1 is the right side direction indicated by the arrow in FIG.
[0013]
The LED 21 is arranged so as to be positioned on the optical axis of the imaging optical path indicated by reference numeral 20 in FIG. 2 when the body cap 2 is attached to the lens mount portion 11. The LED 21 is used as a light source to capture a foreign object detection image. At this time, by making the size of the LED 21 sufficiently small with respect to the distance to the image sensor, this light source can be regarded as a point light source. In a general Bayer array image sensor, since many elements corresponding to G (green) among RGB colors are arranged, when the light source is monochromatic light, the image sensor is sensitive to green light. Is particularly expensive. Further, when the light source is white light, all the RGB color components are included in the light source, so that light can be detected by all elements. Therefore, it is preferable to use an LED that emits green or white light as the LED 21.
[0014]
The pilot lamp 22 is composed of, for example, a light emitting element such as an LED, and is arranged so that the lighting state can be visually recognized from the outside when the body cap 2 is attached to the lens mount portion 11. By turning on the pilot lamp 22 in synchronization with the lighting of the LED 21, the user can easily check the lighting state of the LED 21 from the outside without looking through the viewfinder of the camera.
[0015]
The switch 23 is a switch for switching on / off of the LED 21 and the pilot lamp 22 when operated by the user. The switch 23 is preferably structured so as not to switch unexpectedly in a camera bag or the like. For example, a structure in which two operation parts are switched simultaneously by pressing, a structure that prevents unexpected operation by a spring or a fixture, or a structure in which a cover is attached to the operation part can be considered.
[0016]
The battery 24 supplies power for operating each electrical component of the body cap 2 such as the LED 21 and the pilot lamp 22. For example, a button battery is used as the battery 24. The electric circuit board 25 includes a circuit pattern for electrically connecting the LED 21, the pilot lamp 22, the switch 23, and the battery 24, and various other electric components. The electric circuit board 25 incorporates an auto power-off function that automatically turns off the LED 21 to prevent unnecessary battery consumption when the LED 21 continues to be lit for a predetermined time, for example, 30 seconds.
[0017]
Next, a method for capturing a foreign object detection image using the body cap 2 described above will be described. When capturing a foreign object detection image, the user first attaches the body cap 2 to the lens mount unit 11 and then sets the imaging conditions. Imaging conditions set at this time are sensitivity, shutter speed, and white balance. As these set values, those determined in advance by measurement so as to obtain an image having appropriate luminance when the LED 21 is used as a light source are used. As described above, the LED 21 is regarded as a point light source. Further, since the body cap 2 is not provided with a diaphragm mechanism, it is not necessary to set a diaphragm as an imaging condition.
[0018]
After setting the imaging conditions, the user operates the switch 23 to turn on the LED 21, and then performs imaging based on the set imaging conditions by operating a release button (not shown). In addition, it is good also as imaging after setting LED21 after lighting LED21. The foreign object detection image data obtained by this imaging is output from the imaging unit 12 to the memory card 13 and recorded in the same manner as normal captured image data. After capturing the foreign object detection image, the LED 21 is turned off by the operation of the switch 23 or the aforementioned auto power off function.
[0019]
The foreign object detection image data thus recorded on the memory card 13 is read into the personal computer 4. The personal computer 4 calculates the position of the foreign matter on the imaging optical path attached to the optical member using the foreign matter detection image data by executing the foreign matter detection program. The method will be described next.
[0020]
(2) Foreign object position calculation
In the foreign object detection image obtained as described above, a shadow caused by the foreign object attached to the optical member of the imaging unit 12 is captured. 3A and 3B show examples of the relationship between the position of the foreign object shadow in the captured image and the position of the foreign object attached to the optical member. FIG. 3A shows a case where the foreign matter is point-like, and the point-like foreign matter 33 is attached to the optical member 32 on the imaging optical path in front of the imaging surface 31. At this time, in the foreign object detection image captured using the LED 21 as a point light source, if a shadow of the foreign object 33 is imaged at a distance r ′ from the optical axis 20, the position from the optical axis 20 to the position where the foreign object 33 is attached is taken. The distance r is represented by the following formula (1).
[Expression 1]
r = r ′ · (L−d) / L (1)
However,
L: Distance from the imaging surface 31 to the LED 21
d: Distance from the imaging surface 31 to the foreign object 33 (distance from the imaging surface 31 to the surface of the optical member 32)
[0021]
FIG. 3B shows a case where the foreign matter is planar. A planar foreign material 34 is attached on the optical member 32, and a distance r from the optical axis 20 in the captured image.₁'~ R₂It is assumed that the shadow of the foreign object 34 is captured in the range '. At this time, the distance r from the optical axis 20 to the range where the foreign matter 34 is attached.₁And r₂Is represented by the following formula (2) as in the case of FIG.
[Expression 2]
r₁= R₁′ · (Ld) / L
r₂= R₂′ · (L−d) / L (2)
[0022]
For example, the personal computer 4 determines from the read image data for foreign object detection that a luminance difference between a pixel whose luminance value is equal to or less than a threshold value, a luminance value of an adjacent pixel, or an average luminance value of an image is equal to or greater than the threshold value. Pixels and the like are detected and used as foreign object shadows. Further, the position of the foreign matter on the imaging optical path attached to the optical member 32 is calculated from the detected shadow position of the foreign matter using the relationship as described above. The personal computer 4 stores the position of the foreign matter calculated in this manner, and when the captured image normally captured by the camera body 1 is read, the captured image is generated by the foreign matter based on the stored position of the foreign matter. Correct image defects. Next, a method for correcting the image defect will be described.
[0023]
(3) Image defect correction
The position and size of the image defect in the captured image can be estimated based on the position of the foreign matter on the imaging optical path calculated as described above, the exit pupil distance at the time of imaging, and the size of the stop. For example, there is a relationship shown in FIG. 3A between the position of the image defect due to the point-shaped foreign matter when the diaphragm is minimized, the position of the foreign matter on the imaging optical path, and the exit pupil distance at the time of imaging. It holds. At this time, the distance L from the imaging surface 31 to the LED 21 corresponds to the exit pupil distance, and an image defect appears at a position r ′ from the optical axis 20 due to a foreign object located at a distance r from the optical axis 20. That is, the position of the image defect is determined by the position of the foreign matter on the imaging optical path and the exit pupil distance at the time of imaging.
[0024]
On the other hand, the size of the image defect varies depending on the size of the stop. This is shown in FIGS. 4 (a) and 4 (b). FIG. 4A shows a case where the F value representing the size of the stop is large, that is, a case where the stop is small, and FIG. 4B shows a case where the F value is small, that is, a case where the stop is large. Based on the relationship shown in FIG. 4 and the F value definition formula (F = focal length / lens effective aperture), the distance d from the imaging surface to the position of the foreign object and the spread Γ of the foreign object shadow are expressed by the following formula ( Represented by 3). Thus, the size of the image defect is determined by the size of the stop.
[Equation 3]
Γ = d / F (3)
[0025]
As described above, the position and size of the image defect with respect to the spot-like foreign material can be determined based on the position of the foreign material on the imaging optical path, the exit pupil distance at the time of imaging, and the size of the stop. In the same way for planar foreign matter, the position and size of the image defect are determined based on the position of the foreign matter on the imaging optical path, the exit pupil distance at the time of imaging, and the size of the stop. can do. Thus, the position and size of the image defect in the captured image can be estimated by determining the position and size of the image defect with respect to the detected foreign matter on the imaging optical path.
[0026]
The personal computer 4 estimates the position and size of the image defect in the captured image based on the relationship described above based on the position of the foreign matter calculated from the read foreign matter detection image. Further, the pixel information corresponding to the estimated image defect is corrected in the read captured image. The correction of the pixel information at this time is performed, for example, by replacing the pixel value of the pixel determined to be an image defect with the pixel value of a pixel closest to the pixel and not at the position of the image defect. Information regarding the exit pupil distance and the aperture size is recorded in the memory card 13 together with the captured image data at the time of imaging, and is simultaneously read when the captured image data is read by the personal computer 4.
[0027]
In this way, it is possible to correct an image defect of a captured image that is normally captured based on the position of the foreign object on the imaging optical path calculated from the foreign object detection image. Note that the image defect correction process is not necessarily performed on the captured image, and the user may select whether to perform the image defect correction process for each captured image.
[0028]
As described above, the foreign object detection system of FIG. 1 takes a foreign object detection image using the body cap 2 as a jig. The captured foreign object detection image is output to the personal computer 4 by mounting the memory card 13 on the memory card reader 6 or by connecting the output interface 14 and the personal computer 4. When the foreign object detection image is output to the personal computer 4, as shown in FIG. 5, the personal computer 4 reads the foreign object detection image (step S21), detects the foreign object on the imaging optical path, and calculates its position. (Step S22). Thereafter, the personal computer 4 reads a captured image obtained by normal imaging of the camera body 1 recorded in the memory card 13 (step S23), and corrects an image defect in the captured image (step S24).
[0029]
According to the foreign substance detection system described above, the following operational effects can be obtained.
(1) Since the body cap 2 used as a jig when capturing a foreign object detection image is provided with the LED 21, it is possible to capture a foreign object detection image without incorporating a dedicated light source in the camera body. it can. Since the LED 21 is positioned on the optical axis of the imaging optical path when the body cap 2 is attached to the lens mount unit 11, the position of the foreign substance on the imaging optical path is calculated from the captured foreign object detection image. be able to.
(2) Since the body lamp 2 is provided with the pilot lamp 22, the switch 23, the battery 24, and the electric circuit board 25, it is possible to check the lighting state of the LED 21 from the outside, switch the LED 21 on and off, and switch to the LED 21. It is possible to realize power supply and auto power-off in which the LED 21 is automatically turned off after a predetermined time has elapsed. Therefore, a foreign object detection image can be taken with an existing camera body, and the usability of the body cap 2 can be improved.
(3) By using an LED that emits white or green light as the LED 21, it is possible to effectively detect foreign matter on the imaging optical path from the captured foreign matter detection image.
(4) Since the camera body 1 records information about the aperture and exit pupil distance during normal imaging together with the captured image data, the personal computer 4 uses this information to detect the position and size of the image defect in the captured image. And the image defect can be corrected.
[0030]
-Second Embodiment-
A second embodiment of the foreign matter detection system to which the present invention is applied is shown in FIG. The camera body 1A in FIG. 6 captures a foreign object detection image by automatically setting the imaging conditions and turning on the point light source by switching to the foreign object detection mode. The camera body 1A is different from the camera body 1 of FIG. 1 in that it includes a control unit 17A that replaces the control unit 17 and a mode setting unit 15. Further, instead of the body cap 2, a body cap 2A is attached to the lens mount portion 11 of the camera body 1A. Since other points are the same as those of the first embodiment, description thereof will be omitted below.
[0031]
The mode setting unit 15 causes the control unit 17A to select one of an imaging mode for performing normal imaging using the lens 3 and a foreign object detection mode for capturing a foreign object detection image using the body cap 2A as a jig. Set. The mode setting is automatically switched by detecting that the body cap 2A is attached to the lens mount unit 11.
[0032]
An example of the structure of the body cap 2A is shown in FIG. The body cap 2A is provided with a plurality of terminals 26. The lens mount unit 11 of FIG. 6 includes a terminal (not shown) that contacts the terminal 26, and the body cap 2 </ b> A inputs a control signal from the control unit 17 </ b> A through the terminal 26. Further, when the terminal 26 is in contact with the terminal of the lens mount unit 11, the signal level of the terminal changes, and the mode setting unit 15 can detect that the body cap 2 </ b> A is attached. The body cap 2A does not have a configuration corresponding to the switch 23 and the battery 24 of FIG. 2, and the control of turning on / off the LED 21 and the power supply to the LED 21 are performed by the camera body 1A via the terminal 26. .
[0033]
The processing contents when the camera body 1A captures a foreign object detection image using the body cap 2A will be described with reference to the flowchart of FIG. When the body cap 2A is attached to the lens mount unit 11 (YES in step S1), the mode setting unit 15 switches the control unit 17A from the imaging mode to the foreign object detection mode (step S2), and the control unit 17A detects the foreign object. The imaging conditions for the image for use are automatically set (step S3). Imaging conditions set at this time are the same as those set by the user in the first embodiment, and are sensitivity, shutter speed, and white balance. As these setting values, those determined in advance by measurement so as to obtain an image having appropriate luminance are used.
[0034]
When the imaging conditions are set in this way and the user instructs to capture a foreign object detection image (YES in step S4), the control unit 17A outputs a control signal to the body cap 2A to light the LED 21 (step S5). Subsequently, the imaging unit 12 captures a foreign object detection image (step S6). The captured foreign object detection image is recorded in the memory card 13 (step S7). Note that after capturing the foreign object detection image, the control unit 17A turns off the LED 21.
[0035]
In addition, when the lens 3 is attached to the lens mount unit 11 instead of the body cap 2A (step S1 is NO and step S8 is YES), and the user instructs to take an image (step S9 is YES), the control unit 17A Performs normal imaging by the imaging unit 12 (step S10). This captured image is recorded on the memory card 13 (step S7).
[0036]
In this way, the foreign object detection image and the captured image recorded in the memory card 13 in step S7 are attached to the memory card reader 6 or the output interface 14 and the personal computer 4 are connected. It is output to the personal computer 4. When the personal computer 4 reads the foreign object detection image, the personal computer 4 performs processing similar to that in the first embodiment (see FIG. 5) to correct image defects in the captured image.
[0037]
According to the foreign substance detection system described above, the following operational effects can be obtained.
(1) Since the body cap 2A is supplied with the power of the LED 21 from the external camera body 1A and the lighting state of the LED 21 is further controlled, the structure of the body cap 2A can be simplified.
(2) The camera body 1A has a foreign object detection mode for capturing a foreign object detection image. When this foreign object detection mode is selected, an imaging condition is automatically set. Further, when a foreign object detection image is taken, the lighting state of the LED 21 is controlled. Since it did in this way, the image for a foreign material detection can be imaged easily.
(3) Since the foreign object detection mode is automatically selected when the body cap 2A is attached to the lens mount unit 11, the foreign object detection mode can be easily selected.
[0038]
In the foreign object detection system described above, the foreign object detection mode may be selected by a user operation. In this case, switching between the foreign object detection mode and the imaging mode is performed by operating a mode selection switch provided in the camera body 1A. Further, the determination process in step S1 in FIG. 8 is performed depending on which mode the mode selection switch is switched to. If the mode selection switch is switched to the foreign object detection mode, YES. If the mode selection switch is switched to the imaging mode, NO. And
[0039]
-Third embodiment-
A third embodiment of the foreign object detection system to which the present invention is applied is shown in FIG. The camera body 1B in FIG. 9 automatically captures a foreign object detection image according to the set execution conditions. The camera body 1B is different from the camera body 1A according to the second embodiment in that it has a condition setting unit 16. Since other points are the same as those of the second embodiment, description thereof will be omitted below.
[0040]
The condition setting unit 16 automatically sets a condition for executing imaging of a foreign object detection image. The execution conditions set at this time may be, for example, the time, date and time, the elapsed time since the previous foreign object detection image was captured, the number of lens replacements, the number of imaging operations, and the like. When it is detected that the set execution condition is satisfied and the body cap 2A is attached to the lens mount unit 11, the control unit 17A is automatically switched to the foreign object detection mode by the mode setting unit 15, and the imaging unit 12 Thus, the foreign object detection image is automatically captured.
[0041]
The foreign object detection image data automatically captured in this way is recorded in the memory card 13. By attaching the memory card 13 to the memory card reader 6 or connecting the output interface 14 and the personal computer 4, the data for the foreign object detection image is output to the personal computer 4 and read into the personal computer 4. The personal computer 4 performs the same processing as in the first and second embodiments, and corrects image defects in the captured image using the foreign object detection image.
[0042]
FIG. 10 shows a flowchart of processing for automatically capturing a foreign object detection image, which is executed in the camera body 1B. This process is always executed during the operation of the camera body 1B.
[0043]
In step S31, it is determined whether or not the execution condition for capturing the foreign object detection image set in the condition setting unit 16 is satisfied. If the execution condition is satisfied, for example, if the set time or date is exceeded, or if the number of lens replacements or the number of imaging is greater than the set number, the process proceeds to step S32. If the execution condition is not satisfied, step S31 is repeatedly executed. During this period, the imaging mode is set and a normal camera imaging operation is performed. In the determination in step S31, various count values that differ depending on the execution conditions, for example, count values such as the elapsed time since the previous image for detecting a foreign object, the number of lens replacements, and the number of image captures are used. . These count values are appropriately counted up based on the respective count conditions.
[0044]
In step S32, it is determined whether or not the body cap 2A is attached to the lens mount portion 11. If it is attached, the process proceeds to step S33. If not attached, the process returns to step S31. At this time, it is preferable to urge the user to attach the body cap 2A and take a foreign object detection image by displaying on a display (not shown).
[0045]
In step S33, the mode setting unit 15 switches from the imaging mode to the foreign object detection mode. In the next step S34, the imaging condition for the foreign object detection image is set in the control unit 17A. At this time, as in the second embodiment, the sensitivity, shutter speed, and white balance are set to preset values determined by measurement so that an image with appropriate luminance can be obtained.
[0046]
In step S35, the LED 21 of the body cap 2A shown in FIG. 7 is turned on, and in the next step S36, an image for detecting foreign matter is captured by the imaging unit 12. The captured foreign object detection image data is recorded in the memory card 13 in step S37. In step S38, the count value used in the determination in step S31 is cleared, and in the next step S39, the mode setting unit 15 switches from the foreign object detection mode to the imaging mode. After step S39 is executed, the process returns to step S31, and the process of FIG. 10 is repeated again.
[0047]
According to the foreign matter detection system described above, the foreign matter detection mode is automatically executed when the set execution condition is satisfied and the body cap 2A is attached, and the foreign matter detection image is captured. Since it did in this way, the image for a foreign material detection can be imaged regularly and automatically by setting an execution condition.
[0048]
In each of the above-described embodiments, an individual number or individual symbol for identifying an individual camera body may be recorded together with a captured image including a foreign object detection image. By doing so, it is possible to automatically identify which camera body is the captured image when processing the captured images from the plurality of camera bodies with the same personal computer. That is, the calculated position of the foreign object is stored for each camera body.
[0049]
In each of the above-described embodiments, the camera bodies 1, 1A and 1B and the body caps 2 and 2A may be used by appropriately rearranging the configurations. For example, the body cap 2A may have a configuration corresponding to the battery 24 of the body cap 2, and the power of the LED 21 and the pilot lamp 22 may be supplied by this battery.
[0050]
In each of the embodiments described above, the foreign matter detection jig is realized by the body cap 2 or 2A, the light source is the LED 21, the pilot lamp is the pilot lamp 22, the switch is the switch 23, the power supply means is the battery 24, and the auto power off means is The electric circuit board 25 and the power supply means are realized by the terminals 26, respectively. Further, the camera body is realized by any one of the camera body 1, 1A or 1B, the mode setting means is the mode setting section 15, the execution condition setting means is the condition setting section 16, the imaging condition setting means, the lighting control means, and the foreign object imaging command. Each means is realized by the control unit 17A. However, these are merely examples, and each component is not limited to the above-described embodiment as long as the characteristics of the present invention are not impaired.
[0051]
【The invention's effect】
Since the present invention is configured as described above, in the interchangeable lens digital camera, it is possible to detect foreign matter on the imaging optical path without incorporating a dedicated light source in the camera body.
[Brief description of the drawings]
FIG. 1 is a diagram showing a first embodiment of a foreign object detection system according to the present invention.
FIG. 2 is a diagram showing an example of a body cap in the first embodiment
FIGS. 3A and 3B are diagrams illustrating an example of the relationship between the position of a shadow of a foreign object and the position of a foreign object attached to an optical member in a captured image. FIG. 3A illustrates a case where the foreign object is a dot, and FIG. Each case is shown.
FIGS. 4A and 4B are diagrams illustrating a state in which the size of an image defect in a captured image changes depending on the size of a diaphragm, where FIG. 4A illustrates a case where the diaphragm is small and FIG. 4B illustrates a case where the diaphragm is large.
FIG. 5 is a flowchart showing a processing flow of foreign object position calculation and image defect correction in a personal computer.
FIG. 6 shows a second embodiment of the foreign object detection system according to the present invention.
FIG. 7 is a diagram showing an example of a body cap in the second and third embodiments.
FIG. 8 is a flowchart showing a processing flow when capturing a foreign object detection image in the second embodiment.
FIG. 9 is a diagram showing a third embodiment of the foreign object detection system according to the present invention.
FIG. 10 is a flowchart illustrating a processing flow when a foreign object detection image is captured in the third embodiment.
[Explanation of symbols]
1, 1A, 1B: Camera body 2, 2A: Body cap
3: Lens 4: PC
5: Monitor 6: Memory card reader
11: Lens mount part 12: Imaging part
13: Memory card 14: Output interface
15: Mode setting unit 16: Condition setting unit
17, 17A: Control unit 21: LED
22: Pilot lamp 23: Switch
24: Battery 25: Electric circuit board
26: Terminal

Claims (15)

Used to detect foreign objects present on the imaging optical path of interchangeable lens digital cameras,
Mounting means for mounting to the lens mount portion of the digital camera;
A light source located on the optical axis of the imaging optical path when attached to the lens mount portion by the attachment means;
A foreign matter detection jig comprising a power supply terminal for supplying power to the light source from the outside . Used to detect foreign objects present on the imaging optical path of interchangeable lens digital cameras,
Mounting means for mounting to the lens mount portion of the digital camera;
A light source located on the optical axis of the imaging optical path when attached to the lens mount portion by the attachment means;
A foreign matter detection jig comprising a pilot lamp that indicates the lighting state of the light source to the outside . Used to detect foreign objects present on the imaging optical path of interchangeable lens digital cameras,
Mounting means for mounting to the lens mount portion of the digital camera;
A light source located on the optical axis of the imaging optical path when attached to the lens mount portion by the attachment means;
A switch for switching on / off the light source by a user operation;
A foreign matter detection jig , comprising: an auto power off unit that turns off the light source after a lapse of a certain time since the light source is turned on . Used to detect foreign objects present on the imaging optical path of interchangeable lens digital cameras,
Mounting means for mounting to the lens mount portion of the digital camera;
A light source located on the optical axis of the imaging optical path when attached to the lens mount portion by the attachment means;
A foreign matter detection jig comprising a signal input terminal for instructing the light source to be turned on and off from the outside . In the foreign matter detection jig according to any one of claims 2 to 4 ,
A foreign matter detection jig, further comprising power supply means for supplying power to the light source. In the foreign matter detection jig according to claim 1 ,
The foreign matter detection jig, wherein the light source is a light source that emits white or green light. In the interchangeable-lens digital camera body that images a foreign object existing on the imaging optical path using the foreign object detection jig according to claim 1 ,
Mode selection means for selecting a foreign object detection mode for imaging the foreign object by a user operation;
A camera main body comprising mode setting means for setting a mode selected by the mode selection means. In the interchangeable-lens digital camera body that images a foreign object existing on the imaging optical path using the foreign object detection jig according to claim 1 ,
A camera body comprising mode setting means for setting a foreign object detection mode for imaging the foreign object when the foreign object detection jig is attached. The camera body according to claim 7 or 8 ,
A camera body, further comprising an imaging condition setting unit that sets an imaging condition for imaging the foreign object when the foreign object detection mode is set. In the lens-interchangeable digital camera body that images a foreign object existing on the imaging optical path using the foreign object detection jig according to claim 4 ,
A camera body comprising lighting control means for controlling lighting of the light source when imaging the foreign object. The camera body of claim 10 ,
Mode setting means for setting a foreign object detection mode for imaging the foreign object;
A camera body, further comprising: an imaging condition setting unit that sets an imaging condition when imaging the foreign object when the foreign object detection mode is set. The camera body according to claim 11 ,
When the predetermined condition is satisfied and the foreign object detection jig is attached , the foreign object detection mode is set by the mode setting unit, and the foreign object is detected under the imaging condition set by the imaging condition setting unit. A camera body, further comprising foreign object imaging command means for commanding imaging. In the camera body according to any one of claims 7 to 12 ,
A camera main body further comprising recording control means for recording information on a diaphragm and an exit pupil distance at the time of imaging together with the captured image. The camera body according to claim 13 ,
The recording control unit records an individual number or an individual symbol for identifying an individual of the camera body together with the captured image. A foreign matter detection system for an interchangeable lens digital camera, comprising the foreign matter detection jig according to any one of claims 1 to 6 and the camera body according to any one of claims 7 to 14 .

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